Claims:1. A method to produce an integral protrusion, the method comprising the steps of:
providing a malleable component to be worked upon by a punch and a die;
performing, on at least a part of the malleable component, a localized action by interaction with any or a combination of the punch and the die; and
obtaining, around the at least a part of the malleable component, a final geometry of the integral protrusion, wherein the final geometry is decided based on a critical parameter related to any or a combination of the malleable component, the punch and the die.
2. The method as claimed in claim 1, wherein the method further comprises the step of applying a light coat of oil on the at least a part of the malleable component before the localized action.
3. The method as claimed in claim 1, wherein the critical parameter is selected from any or a combination of the group consisting of H/T (protrusion depth to malleable component thickness ratio), D/H (protrusion diameter to protrusion depth ratio), D/T (protrusion diameter to malleable component thickness ratio), raw material, and hardness of the malleable component.
4. The method as claimed in claim 1, wherein the localized action is effectuated by single stroke of the punch in three stages: (i) a first stage configured for initial malleable component flow into orifice of the die by side cropping and piercing action, (ii) a second stage configured for the malleable component flow further towards the orifice by piloting and forming actions, and (iii) a third stage with blanking action in accordance with the integral protrusion.
5. The method as claimed in claim 3, wherein specification of the critical parameter are H/T about 1.8, D/H about 1.4, D/T about 2.25, while the malleable component has the raw material as stainless steel IS:513 Grade D, which has hardness in the range of about 100-110 HV.
6. The method as claimed in claim 5, wherein height of the protrusion for the specification is 1.8 times the height of the component.
7. The method as claimed in claim 3, wherein the H/T ratio is from about 1.5 to about 2.5.
8. The method as claimed in claim 3, wherein the D/H ratio is from about 1 to about 2.
9. The method as claimed in claim 3, wherein the D/T ratio is from about 2 to about 4.
10. The method as claimed in claim 1, wherein malleable component thickness
(t) is in the range from about 0.5 mm to about 6 mm.

, Description:TECHNICAL FIELD
[0001] The present disclosure generally relates to the field of manufacturing processes. In particular, the present disclosure pertains to impact extrusion. More specifically, the present disclosure relates to formation of an integral protrusion in a sheet metal component.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Impact extrusion is a discrete manufacturing process, in which a metal part is extruded through the impact of a die with a work stock. The metal part is formed at a high speed and over a relatively short stroke. In standard metal extrusions, the force to extrude the work stock is commonly delivered by way of a hydraulic press. In impact extrusions, mechanical presses are most often employed. The force used to form standard extrusions is usually delivered over a horizontal vector, producing a long continuous product. Interestingly, force used to form impact extrusions is usually delivered over a vertical vector, producing a single part with each impact of the punch. Impact extrusion processes use a combination of tensile & compressive forces to stretch the metal beyond the yield point. This pressure and force is directed locally at an area receiving direct impact. While impact extrusion is most often performed cold. Occasionally with some metals and thicker walled structures, the work is heated before impact forming it. This process is best suited for high ductile metals and malleable metal.
[0004] Technically speaking, impact extrusion can work harden the metal part, which may or may not be desirable. If necessary, a component may be annealed before further processing occurs. From a broader perspective, favorable grain structure, good surface finish and high productivity are some possible advantages of manufacturing by impact extrusion.
[0005] Sheet metal parts find ubiquitous applications in a wide variety of products. The parts produced from sheet metal are essentially consistent in respect of dimensions such as thickness. Therefore, fixing means such as pins are required to be mounted for applications of the sheet metal parts for a variety of functions and other considerations. Said pins maybe machined and then mounted by a variety of assembly processes. There have been efforts in the art whereby an integral protrusion can be formed in a sheet metal so as to eliminate the need of a fixing means (i.e. a pin). Depending upon factors, such as for example but need not necessarily, resource availability and quality expectations, some of the most common methods of producing protrusions can be performed in different ways such as, but not limited to, Hole Flanging, Flaring, Semi piercing, Offsetting or Embossing.
[0006] A major limitation with the implementation of aforementioned methods is limits of protrusion geometry and/or dimensioning whereby protrusion height larger than sheet metal thickness is generally considered as 'non-manufacturable' due to frequently occurring problems such as metal tearing/cracking, tool breakage, surface cracks, excessive metal thinning, etc. Due to this serious constraint the protrusion height is normally restricted to maximum around half (i.e. 50%) of sheet thickness.
[0007] There is a need in the art to provide a simple and efficient method to form an integral protrusion in a sheet metal component so as to obviate aforementioned shortcomings encountered in the art.
[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0010] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

OBJECTS OF THE INVENTION
[0013] A general object of the present disclosure is to provide for a simple, efficient and economical method that obviates shortcomings encountered with conventional sheet metal protrusion processes.
[0014] An object of the present disclosure is to provide an integral protrusion in sheet metal without undesired metal flow during its working.
[0015] An object of the present disclosure is to provide substantially thick protrusion(s) in working of sheet metals.
[0016] Yet another object of the present disclosure is to obviate need for fasteners like pins by ingenious utilization of thick protrusion(s) of sheet metals.

SUMMARY
[0017] Aspects of the present disclosure generally relate to the field of manufacturing processes. In particular, the present disclosure pertains to impact extrusion. More specifically, the present disclosure relates to formation of an integral protrusion in a sheet metal component.
[0018] In an aspect, the present disclosure provides a method to produce an integral protrusion, the method can include the steps of: (i) providing a malleable component, such as sheet metal, to be worked upon by a punch and a die; (ii) performing, on at least a part of the malleable component, a localized action by interaction with any or a combination of the punch and the die; and (iii) obtaining, around the at least a part of the malleable component, a final geometry of the integral protrusion, wherein the final geometry can be decided based on a critical parameter related to any or a combination of the malleable component, the punch and the die.
[0019] In an aspect, aforementioned method of the present disclosure can further comprise the step of applying a light coat of oil (say industrial oil) on at least a part of malleable component before localized action. In an embodiment, component thickness (t) can be in the range from about 0.5 mm to about 6 mm.
[0020] In an aspect, critical parameter for obtaining final geometry (i.e. protrusion) of the present disclosure can be selected from any or a combination of the group consisting of H/T (protrusion depth to malleable component thickness ratio), D/H (protrusion diameter to protrusion depth ratio), D/T (protrusion diameter to malleable component thickness ratio), raw material, and hardness of malleable component.
[0021] In an embodiment, specification of critical parameter can be H/T about 1.8, D/H about 1.4, D/T about 2.25, while the malleable component can have the raw material as stainless steel IS:513 Grade D, which can have a hardness in the range of about 100-110 HV. Moreover, height of the protrusion for the specification can be 1.8 times the height of the component. In an embodiment, H/T ratio can be from about 1.5 to about 2.5, D/H ratio can be from about 1 to about 2 while the D/T ratio can be from about 2 to about 4.
[0022] In an aspect, localized action, in implementation of the present disclosure, can be effectuated by a single stroke of punch in three stages: (i) a first stage configured for initial malleable component flow into orifice of the die by side cropping and piercing action, (ii) a second stage configured for the malleable component flow further towards the orifice by piloting and forming actions, and (iii) a third stage with blanking action in accordance with integral protrusion.
[0023] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0025] FIG.1 illustrates an exemplary sectional view of a punch and a die in accordance to an embodiment of the present disclosure.
[0026] FIG.2 illustrates an exemplary sectional view of formed solid protrusion of a sheet metal in accordance to an embodiment of the present disclosure.
[0027] FIG.3 to 6 illustrate exemplary sectional views of first to last stages of sheet metal forming method in accordance to an embodiment of the present disclosure.
[0028] FIG.7 illustrates an exemplary sectional view of formed solid protrusion subsequent to last stage of sheet metal forming method in accordance to an embodiment of the present disclosure.
[0029] FIG. 8 illustrates an exemplary view of sheet metal with multiple protrusions in accordance to an embodiment of the present disclosure.
[0030] Figure 7 shows the final components formed protrusion by this invention Figure 8 shows the front view of sheet metal component for used for multiple solid projection protrusion

DETAILED DESCRIPTION
[0031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0032] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0033] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0034] Embodiments of the present disclosure generally relate to the field of manufacturing processes. In particular, the present disclosure pertains to impact extrusion. More specifically, the present disclosure relates to formation of an integral protrusion (also referred to as protrusion and these terms used interchangeably hereinafter) in a sheet metal component.
[0035] FIG.1 illustrates an exemplary sectional view of a punch 110 and a die 130 in accordance to an embodiment of the present disclosure. In an aspect, the present disclosure provides a method to produce an integral protrusion 122 (not shown herein while best shown in FIG. 2 and 7), the method can include the steps of: (i) providing a malleable component 120 (also referred to as sheet metal, sheet stock, metal part and these terms used interchangeably hereinafter), to be worked upon by the punch 110 and the die 130; (ii) performing, on at least a part of the malleable component 120, a localized action by interaction with any or a combination of the punch 110 and the die 130; and (iii) obtaining, around the at least a part of the malleable component 120, a final geometry of the integral protrusion 122, wherein the final geometry can be decided based on a critical parameter related to any or a combination of the malleable component 120, the punch 110 and the die 130. Further, the punch 110 can have a punch head 112 (of diameter ØD1) that can readily move into orifice 132 of the die 130 while the malleable component 120 is present therebetween the punch 110 and the die 130.
[0036] In an aspect, malleable component 120, as referred in various aspects, can be a sheet metal of uniform dimensions as particularly shown in FIG. 3. Further, on working in accordance with implementation of the present disclosure, the malleable component 120 can undergo different stages of deformation as illustrated in various figures hereinafter so as to obtain protrusion 122 of the malleable component 120 as shown in FIGS. 2 and 7.
[0037] In an aspect, aforementioned method of the present disclosure can further comprise the step of applying a light coat of oil (say industrial oil) on at least a part of malleable component 120 before localized action. In an embodiment, malleable component 120 thickness (t) can be in the range from about 0.5 mm to about 6 mm.
[0038] As illustrated by FIG. 1, in a preferred aspect of the present disclosure, relation among dimensions of punch 110 and die 130 can be ØD = Die Protrusion Diameter, ØD1 = 0.67D, ØD2 = 1.67D, H = Protrusion Height, H1 = 1.8T, H2 = 0.75T, H3 = 0.38T, R = 0.3T to 0.4T, R1 = 0.2T, R2 = 0.2T, and R3 = 0.4T. A person skilled in the art shall be able to readily use any or a combination of said dimensions without deviating from the scope of the present disclosure.
[0039] In an aspect, the design of punch and/or die can decide the final geometry of protrusion formed. Specially designed punch & die profile, in accordance with the present disclosure, can be used to deform malleable sheet stock by compressing it to the plastic state. It is desirable to produce the protrusion in a single punch stroke because repeated strikes thereof can result in strain hardening of the sheet stock which will then lead to material tearing/cracking. The punch & die surface can be polished for removing the punch machining marks to lower the friction and aiding a smooth material flow between the punch and the die.
[0040] In implementation of an aspect of the present disclosure, a depression is first formed in sheet metal by localized pressure on its one side over an area equal to the external cross sectional area of the depression. To obtain the desired object deformation of sheet to achieve by compressing to a plastic state a first area surrounding the second area of the sheet upon which the deformation is to be formed. The compressive force is applied near to plastic limit of the sheet metal to cause plastic flow. The compressive force can be applied by hydraulic or by conventional high energy impacting method.
[0041] In an aspect, speed of hydraulic or manual, punch and die system, can be increased with auto feeder and an automatic press. Preferably, the surfaces of die and/or punch can be cleaned & lubricated with a light coat of industrial oil or any other oil as evident to a person having knowledge of the pertinent art.
[0042] FIG.2 illustrates an exemplary sectional view of formed solid protrusion 122 of a sheet metal 120 in accordance to an embodiment of the present disclosure. In an aspect, critical parameter for obtaining final geometry (i.e. protrusion) of the present disclosure can be selected from any or a combination of the group consisting of H/T (protrusion depth to malleable component thickness ratio), D/H (protrusion diameter to protrusion depth ratio), D/T (protrusion diameter to malleable component thickness ratio), raw material, and hardness of malleable component.
[0043] In an embodiment, specification of critical parameter can be H/T about 1.8, D/H about 1.4, D/T about 2.25, while the malleable component can have the raw material as stainless steel IS:513 Grade D, which can have a hardness in the range of about 100-110 HV. Moreover, height of the protrusion for the specification can be 1.8 times the height of the component. In an embodiment, H/T ratio can be from about 1.5 to about 2.5, D/H ratio can be from about 1 to about 2 while the D/T ratio can be from about 2 to about 4.
[0044] FIG.3 to 6 illustrate exemplary sectional views of first to last stage of sheet metal 120 forming method in accordance to an embodiment of the present disclosure. In an aspect, localized action, in implementation of the present disclosure, can be effectuated by a single stroke of punch 110 in three stages: (i) a first stage configured for initial malleable component flow into orifice 132 (refer FIG. 1) of die 130 by side cropping and piercing action, (ii) a second stage configured for the malleable component flow further towards the orifice 132 by piloting and forming actions, and (iii) a third stage with blanking action in accordance with integral protrusion 122.
[0045] As illustrated in FIG. 3, malleable component 120 can be placed on surface of die 130 having orifice 132. Then, force is applied by a punch 110 to deform the malleable component 120 in to the orifice 132 with reciprocating force by the fixed die 130. Due to the configuration and design of the die 130 and punch 110, the malleable component 120 flows, as shown in instant figures, in to the orifice 132. FIGS. 4 and 5 illustrate effect of the force applied on the malleable component 120 to gradual deformation. The design of the die 130 is such that the malleable component 120 deforms from its surface to the orifice 132. The malleable component 120 further flows into the orifice 132 while the punch 110 presses it in three steps (in accordance with aspects of the present disclosure) to form solid protrusion 122 between the die 130 and punch 110. As evident, extrusion of the malleable component 120 can be continued until the projection 122 extends to the desired shape and/or size.
[0046] FIG.7 illustrates an exemplary sectional view of formed solid protrusion 122 subsequent to last stage of sheet metal 120 forming method in accordance to an embodiment of the present disclosure. In an aspect, shape of the protrusion 122 can be selected from the group consisting of round, square, rectangle, oval and triangle among any other desired shape with suitable adjustments, to dimensions of die/punch/sheet metal, as would be appreciated by a person having knowledge of pertinent art.
[0047] In an aspect, method of forming solid protrusion 122 from sheet metal 120 can preferably result in the solid protrusion 122 dimension (H) more than 1.8 times of thickness (T) of the sheet metal 120. A series of drawing and punching operation, to the sheet metal 120 can lead to a cup shaped protrusion projection 122. Technically speaking, protrusion 122 can be formed by compressing to a plastic state a first area of the sheet metal 120 to form a cup-like shape and then sufficient compressive load can be applied to its second area to obtain desired protrusion. The first area and second area can be parallel walls of uniform thickness usually thinner than sheet metal thickness (T).
[0048] FIG. 8 illustrates an exemplary view of sheet metal 120 with multiple protrusions 122 in accordance to an embodiment of the present disclosure. Herein, multiple protrusions as marked by 122 can be utilized in various implementation of the sheet metal 120 as would be obvious to a person known in the relevant art. In an aspect, material of sheet metal 120 can be selected from the group consisting of steel, copper, aluminium or any other malleable metal.
[0049] Thus, the present disclosure provides a method for protrusion forming in sheet metals that reduces the number of parts and their assembly costs, and increases productivity, while resulting in an overall reduction in the cost of production.
[0050] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0051] The present disclosure provides a simple, efficient and economical method that obviates shortcomings encountered with conventional sheet metal protrusion processes.
[0052] The present disclosure provides an integral protrusion in sheet metal without undesired metal flow during its working.
[0053] The present disclosure provides provide substantially thick protrusion(s) in working of sheet metals.
[0054] The present disclosure obviates need for fasteners like pins by ingenious utilization of thick protrusion(s) of sheet metals.